Treating infants with 0.2% propranolol eye micro-drops drastically reduced the progression of retinopathy of prematurity

Comparison of Different Doses of Oral and Ocular Propranolol for Retinopathy of Prematurity: A Network Meta-Analysis

OBJECTIVE

The efficacy and safety of propranolol for retinopathy of prematurity (ROP) remain under debate. This network meta-analysis (NMA) focuses on whether a ranking may be established for different dose levels of propranolol as treatment of ROP in terms of stage progression as the primary outcome, with appearance of plus disease and need for anti-vascular endothelial growth factors (anti-VEGFs) or laser therapy as secondary endpoints.

METHODS

Fourteen studies (10 randomised controlled trials, three single-arm trials and one retrospective observational study) of 474 patients treated with oral or ocular propranolol were retrieved from databases up to April 2024. Meta-insight and model-based NMA were undertaken to evaluate the propranolol dose-response relationship. Studies were evaluated for model fit, risk of bias and Confidence of evidence In Network Meta-Analysis (CINeMA). Effect sizes were determined as odds ratio (OR) with 95% credible interval (CrI).

RESULTS

Bayesian analysis showed a trend towards improved effects for propranolol given at late stages (stages 2-3; S23) of ROP progression compared with its administration at earlier stages (stages 0-1; S01). OR values for oral propranolol 1.5 and 2 mg/kg/day given at S23 were 0.13 (95% CrI 0.04-0.37) and 0.16 (95% CrI 0.04-0.61), respectively, while given at S01 were 0.28 (95% CrI 0.02-2.96) and 0.78 (95% CrI 0.14-4.43), respectively. Similarly, OR of eye propranolol 0.2% at S23 was 0.37 (95% CrI 0.09-1.00) versus an S01 OR of 0.64 (95% CrI 0.21-2.04). Surface under the cumulative ranking curve (SUCRA) analyses confirmed best probability values for oral propranolol 1.5-2 mg/kg followed by eye propranolol 0.2%, all at S23. Model-based NMA showed nonlinearity in the dose-response for oral propranolol with a trend to greater maximal effect for its administration at late versus early stages. For secondary endpoints, lower risk values were found with oral propranolol 1.5 mg/kg/day at S23 for progression to plus disease (OR 0.14; 95% CrI 0.02-0.84) and need for anti-VEGFs (OR 0.23; 95% CrI 0.05-0.93) and laser (OR 0.16; 95% CrI 0.02-1.10) therapies also followed by eye propranolol 0.2%, and a similar profile was obtained with SUCRA analysis. Lower doses (0.5-1.0 mg/kg/day) of oral propranolol retained efficacy. Threat of adverse events was estimated as risk difference versus control with no difference for eye propranolol 0.2% and oral propranolol 0.5 mg/kg/day, modest increases of risk for oral propranolol 1.0 and 1.5 mg/kg/day and the highest risk difference for oral propranolol 2.0 mg/kg/day (0.06; 95% CI -0.01 to 0.13).

CONCLUSION

A diminished risk of disease progression and need for additional treatment was obtained with propranolol in ROP, but safety is a potential concern. Propranolol eye micro-drops (0.2%) can be as efficacious as oral propranolol. Nonetheless, the evidence is limited due to the paucity and quality of the available studies.

A promising case of preclinical-clinical translation: β-adrenoceptor blockade from the oxygen-induced retinopathy model to retinopathy of prematurity

Although compartmentalization of the eye seems to promote its experimental manipulation, drug penetration to its posterior part is severely limited by hard barriers thus hindering drug development for eye diseases. In particular, angiogenesis-related retinal diseases share common mechanisms and are responsible for the majority of cases of blindness. Their prevalence is globally increasing mostly because of the increased incidence of systemic pathologies in the adult. Despite the number of preclinical findings demonstrating the efficacy of novel treatments, therapy of retinal neovascular diseases still remains confined to intravitreal anti-vascular endothelial growth factor treatments with some extension to anti-inflammatory therapy. In the mare magnum of preclinical findings aimed to develop novel avenues for future therapies, most compounds, despite their efficacy in experimental models, do not seem to meet the criteria for their therapeutic application. In particular, the groove between preclinical findings and their clinical application increases instead of decreasing and the attempt to bridging the gap between them creates intense frustration and a sense of defeat. In this complex scenario, we will discuss here the role that overactivation of the sympathetic system plays in retinal vessel proliferation in response to hypoxia using the oxygen-induced retinopathy (OIR) model. The potential application of the beta-adrenoceptor (β-AR) blockade with propranolol to the treatment of retinopathy of prematurity will be also discussed in light of preclinical findings in the OIR model and clinical trials using propranolol in preterm infants either per os or as eye drops.

ROP: 80 Years after Its Detection - Where Do We Stand and How Long Will We Continue to Laser?

BACKGROUND

Retinopathy of prematurity (ROP), a potentially blinding disease, is increasing worldwide because of the increased survival of extremely preterm and preterm infants born where oxygen monitoring and ROP screening programs are insufficient. Repeated retinal examinations are stressful for infants, and laser photocoagulation treatment for sight-threatening ROP is destructive. The use of anti-VEGF agents instead of lasers is widespread but requires a long-term follow-up because of late recurrence of the disease. In addition, the optimal anti-VEGF agent dosage and long-term systemic effects require further study.

SUMMARY

Interventions preventing ROP would be far preferable, and systemic interventions might promote better development of the brain and other organs. Interventions such as improved oxygen control, provision of fresh maternal milk, supplementation with arachidonic acid and docosahexaenoic acid, and fetal hemoglobin preservation by reducing blood sample volumes may help prevent ROP and reduce the need for treatment. Free readily available online tools to predict severe ROP may reduce unnecessary eye examinations and select, for screening, those at a high risk of needing treatment.

KEY MESSAGES

Treatment warranting ROP is a sign of impaired neurovascular development in the central nervous system. Preventative measures to improve the outcomes are available. Screening can be refined using tools that can predict severe ROP. Laser treatment and anti-VEGF agents are valuable treatment modalities that may complement each other in recurrent ROP.

Effectiveness of Propranolol in Preventing Severe Retinopathy of Prematurity: A Comprehensive Systematic Review and Meta-Analysis

PURPOSE

To learn more about the effectiveness of oral propranolol as a therapeutic alternative for preterm newborns with pre-existing retinopathy of prematurity (ROP) as well as an early prevention method for ROP, one of the most common but avoidable causes of juvenile blindness.

STUDY DESIGN

Meta-analysis of relevant literature.

METHODS

A total of 3464 papers were identified, with 2873 from PubMed, 39 from Scopus, 67 from Medline, and 16 from Embase. After screening, finally, a total of 8 studies were deemed suitable for review. Following the PRISMA guidelines, published literature was systematically assessed up to May 10, 2023. Trials and observational studies were included in which beta blockage was used to prevent severe ROP (defined as stage ≥3 or requiring treatment). A total of 3646 papers were identified, with 2873 from PubMed, 39 from Scopus, 67 from Medline, and 16 from Embase. After screening, a total of 8 studies were deemed suitable for review.

RESULTS

The use of propranolol is linked to a lower risk of disease development in ROP compared to other therapies or control groups, according to the overall risk ratio of 0.59 (95% CI = 0.42, 0.82; P = .002, I2 = 41%). Additionally, the overall risk ratio for plus disease is 0.42 (95% CI = 0.23, 0.78; P = .006, I2 = 0%), for laser photocoagulation is 0.48 (95% CI = 0.31, 0.74; P = .001; I2 = 2%), and for intravitreal injection of VEGF is 0.43 (95% CI = 0.24, 0.74; P = 0.003, I2 = 0%), suggesting that use of propranolol may reduce the likelihood of developing a disease such as plus disease, requiring laser photocoagulation or necessitating intravitreal injection of vascular endothelial growth factor for ROP, respectively. No statistically significant heterogeneity was found in this study (P > .10, I2 = 50%). It can be concluded from this that the results of the chosen studies were sufficiently comparable and consistent.

CONCLUSION

This study showed that oral propranolol given as a preventive treatment in premature newborns successfully prevented severe ROP. Propranolol dosage and timing must now be carefully considered in the context of the study population, as these factors may have a major impact on the observed outcomes and treatment success.

Propranolol: a new pharmacologic approach to counter retinopathy of prematurity progression

Despite the evident progress in neonatal medicine, retinopathy of prematurity (ROP) remains a serious threat to the vision of premature infants, due to a still partial understanding of the mechanisms underlying the development of this disease and the lack of drugs capable of arresting its progression. Although ROP is a multifactorial disease, retinal vascularization is strictly dependent on oxygen concentration. The exposition of the retina of a preterm newborn, still incompletely vascularized, to an atmosphere relatively hyperoxic, as the extrauterine environment, induces the downregulation of proangiogenic factors and therefore the interruption of vascularization (first ischemic phase of ROP). However, over the following weeks, the growing metabolic requirement of this ischemic retina produces a progressive hypoxia that specularly promotes the surge of proangiogenic factors, finally leading to proliferative retinopathy (second proliferative phase of ROP). The demonstration that the noradrenergic system is actively involved in the coupling between hypoxia and the induction of vasculogenesis paved the way for a pharmacologic intervention aimed at counteracting the interaction of noradrenaline with specific receptors and consequently the progression of ROP. A similar trend has been observed in infantile hemangiomas, the most common vascular lesion of childhood induced by pre-existing hypoxia, which shares similar characteristics with ROP. The fact that propranolol, an unselective antagonist of β1/2 adrenoceptors, counteracts the growth of infantile hemangiomas, suggested the idea of testing the efficacy of propranolol in infants with ROP. From preclinical studies, ongoing clinical trials demonstrated that topical administration of propranolol likely represents the optimal approach to reconcile its efficacy and maximum safety. Given the strict relationship between vessels and neurons, recovering retinal vascularization with propranolol may add further efficacy to prevent retinal dysfunction. In conclusion, the strategy of contrasting precociously the progression of the disease appears to be more advantageous than the current wait-and-see therapeutic approach, which instead is mainly focused on avoiding retinal detachment.